心房快速起搏致扩张型心肌病犬模型心肌基质细胞衍生因子-1及其受体的表达

Expression of Stromal cell-derived factor-I and it's receptor CXCR4 in dilated cardiomyopathy canines who received chronic rapid atrial pacing

目的观察心房快速起搏诱发扩张型心肌病犬模型心肌基质细胞衍生因子-1(SDF-1)及其受体CXCR4的表达。方法选用成年健康杂种犬13条,随机分为2组：快速起搏组7条,假手术组6条。均开胸于右心耳缝植AOO型起搏器,快速起搏组以400次/min起搏6周,假手术组不起搏。心脏彩超定期观察犬的心脏结构与功能。在实验结束时,应用逆转录-聚合酶链反应(RT-PCR)测定左心房和左心室心肌组织中SDF-1和CXCR4 mRNA表达水平。结果快速起搏组各犬不同程度出现心功能降低,与假手术组比较,该组左心房心肌组织中SDF-1和CXCR4 mRNA表达水平分别增加22．4%和18．8%,两组比较差异有统计学意义(t值分别为2．624、2．269,P＜0．05)；左心室心肌组织中SDF-1和CXCR4 mRNA表达水平与假手术组比较,差异无统计学意义(t值分别为0．133、0．525,P＞0．05)。结论心房快速起搏诱发扩张型心肌病犬模型中心房组织SDF-1和CXCR4 mRNA表达水平增高。

Objective To investigate the myocardial expression of stromal cell-derived factor-1 （SDF-1） and it＇s receptor CXCR4 in dilated cardiomyopathy canines induced by chronic rapid atrial pacing. Methods 13 canines were randomly divided into two groups： sham-operated group（n = 6） and atrial pacing group（n = 7）. A pacemaker（AOO） was implanted to the right atrial appendage in each of the dogs. The dogs in atrial pacing group were paced at 400 beats per minute for 6 weeks while those in the sham-operated group were not paced. The structures and functions of the hearts were observed by ultrasound. At the end of the research, SDF-1 and CXCR4 gene expression in myocardium of atrium and ventricle were analyzed at mRNA level by reverse transcription polymerase chain reaction. Results All the dogs in the atrial pacing group suffered from heart failure. Compared with the sham-operated group, chronic rapid atrial pacing significantly increased the expression of SDF-1 and CXCR4 at mRNA level in left atrium （t = 2.624, t = 2.269, P 〈 0.05） while the expression of SDF-1 and CXCR4 at mRNA level in left ventricle showed no significant difference （t = 0.133, t = 0.525, P〉0.05）. Conclusions The expressions of SDF-1 and CXCR4 at mRNA level in atrium significantly increase in dilated cardiomyopathy canines who have received chronic rapid atrial pacing.